Fluid reservoir for a paint spray gun

ABSTRACT

The invention relates to a fluid reservoir for a paint spray gun, comprising a cup-shaped receptacle ( 1 ), a lid ( 2 ) that can be placed thereon ( 1 ) and a connecting part ( 3 ) which can be formed on the receptacle ( 1 ) or on the cover ( 2 ) and which is used to secure the fluid reservoir to the paint spray gun. According to the invention, a transition area ( 12 ) between the connecting part ( 3 ) and the receptacle ( 1 ) or the cover is embodied in a flexible manner in order to adjust the inclination of the receptacle ( 1 ) or the cover ( 2 ) in relation to the central axis ( 14 ) of the connecting part ( 3 ) in order to improve material guiding, even when the paint spray gun is inclined positions.

FIELD OF THE INVENTION

The invention pertains to a fluid reservoir for a paint spray gun.

BACKGROUND OF THE INVENTION

Conventional fluid reservoirs for paint spray guns usually feature acup-shaped receptacle, the underside of which is provided with anopening and a connecting part for detachably connecting the receptacleto the upper side of the paint spray gun. The connecting part is usuallyrealized in the form of a connection piece that is arranged on thebottom of the receptacle and features an external thread that is screwedinto a corresponding threaded opening on the upper side of the paintspray gun. In conventional fluid reservoirs, the connecting part isnormally arranged rigidly on the receptacle. However, this results inthe receptacle assuming a horizontal or nearly horizontal position whenit is attached to the paint spray gun and the paint spray gun is held incertain inclined positions. In this case, the feed of the paint to thepaint spray gun may no longer be ensured under certain circumstances.

SUMMARY OF THE INVENTION

The invention is based on the objective of developing a fluid reservoirof the initially mentioned type that makes it possible to improve thematerial feed, namely also when the paint spray gun is held in inclinedpositions.

This objective is attained with a fluid reservoir with thecharacteristics as set forth in the claims. Practical embodiments andadvantageous additional refinements of the invention form the objects ofthe dependent claims.

One significant advantage of the inventive fluid reservoir can be seenin that the fluid receptacle can be inclined relative to the connectingpart. If so required, the inclination of the fluid reservoir attached tothe paint spray gun can be changed in order to also ensure the inflow ofpaint if the paint spray gun is significantly inclined. Thisadjustability is realized in that the transition area between theconnecting part and the receptacle or the cover is realized in aflexible fashion. The connecting part for detachably Fixing the fluidreservoir on the paint spray gun may be arranged on the receptacle or onthe cover. If the connecting part is arranged on the cover, thereceptacle is situated upside down in its operative position.

In one embodiment of the invention that provides certain advantages withrespect to the manufacturing technology, the wall thickness changes froma greater wall thickness on the connecting part to a lesser wallthickness on the receptacle or the cover in the transition area betweenthe connecting part and the receptacle or the cover.

In another embodiment, the transition area may also be realized, forexample, in the form of a bellows or the like.

BRIEF DESCRIPTION OF THE DRAWINGS

Other special features and advantages of the invention result from thefollowing description of one preferred embodiment that refers to thefigures. Shown are:

FIG. 1, a first embodiment of an inventive fluid reservoir with astraight and an inclined connecting part, wherein the areas X, X1 and Yare illustrated in an enlarged fashion, with area X1 showing the outletspout integral with the cover, and

FIG. 2, a second embodiment of an inventive fluid reservoir with astraight and an inclined connecting part, wherein the areas X and Y areillustrated in an enlarged fashion.

DETAILED DESCRIPTION OF THE INVENTION

The fluid reservoirs for a paint spray gun illustrated in FIGS. 1 and 2comprise a cup-shaped receptacle 1, a cover 2 that can be attached tothe receptacle 1 and a connecting part 3 that is integrally molded ontothe receptacle 1 and that serves for detachably fixing the receptacle 1on a paint spray gun. The receptacle 1 with the connecting part 3integrally molded thereon as well as the cover 2 are realized in theform of injection-molded parts of an elastic, non-embrittling plasticmaterial. These requirements are fulfilled, e.g., with plasticsconsisting of PE or plastics with high PE content.

The enlarged details X and Y in FIGS. 1 and 2 show that the connectingpart 3 consists of a tubular connection piece that is integrally moldedor otherwise integrally connected to the conical bottom 4 of thereceptacle 1, wherein this tubular connection piece comprises ahollow-cylindrical front area 5, an adjacent external thread 6 forscrewing into a conventional internal thread, a screw-type wedge elementthat is arranged above the external thread 6 and that serves forrealizing a rapid-action coupling between the fluid reservoir and thepaint spray gun, and an upper insert area 7 with an inner annularcontact surface 8 for inserting a conventional filter. In the embodimentshown, the screw-type wedge element is formed by a wedge-shapedprojection 9 with a wedge surface 10 that extends approximately overhalf the circumference of the connecting part 3 and engages with acorresponding mating surface on an attachment or projection of the paintspray gun. The projection 9 with the wedge surface 10 and thecorresponding mating surface on the paint spray gun are realized in sucha way that the receptacle 1 can already be tightly fixed on the paintspray gun by turning the two components relative to one another byone-quarter to one-half revolution. The front face 11 of the connectingpart 3 is pressed against a corresponding sealing surface within thepaint spray gun in this case. The additional external thread 6 makes itpossible to utilize the fluid reservoir on paint spray guns that are notequipped with a corresponding fitting for the screw-type wedge element,but rather a conventional internal thread.

In the fluid reservoirs shown in FIGS. 1 and 2, the transition area 12between the connecting part 3 and the bottom 4 of the reservoir 1 isrealized in a flexible fashion such that the angular position of thecentral axis 13 of the reservoir 1 can be adjusted relative to thecentral axis 14 of the connecting part 3. The transition area 12 isrealized in such a way that the reservoir 1 can be held at a desiredincline after it is screwed on the paint spray gun and does notautomatically pivot back into its normal position. If so required, thereservoir 1 can be pivoted back into its normal position or into anotherinclined position. The fluid reservoir is illustrated in its normalposition in the left portions of FIGS. 1 and 2. In this position, thecentral axis 13 of the reservoir 1 coincides with the central axis 14 ofthe connecting part 3. In the right portions of these figures, thereservoir 1 is inclined relative to the connecting part 3. The centralaxis 14 of the connecting part 3 is angled relative to the central axis13 of the reservoir 1 in this case.

In the embodiment shown in FIG. 1, the transition area 12 between theconnecting part 3 and the reservoir 1 is realized in such a way that thewall thickness changes from a greater wall thickness on the insert area7 of the connecting part 3 to a lesser wall thickness on the bottom 4 ofthe reservoir. The difference in wall thickness at the transition areaamounts to at least 30%. This ensures that the bottom 4 of the reservoir1 can be bent without creating cracks and that any impairment of theinsert area 7 of the connecting part 3 is simultaneously prevented. Dueto this measure, the inner contour of the connecting part 3 thataccommodates the filter is also maintained when the reservoir 1 ispivoted. A radius 15 is provided at the transition from the connectingpart 3 to the bottom 4 of the reservoir 1. This ensures that thereservoir 1 is not damaged or bent in this region when it is inclined.

In the embodiment shown in FIG. 2, the transition area 12 is realized inthe form of a bellows. The reservoir 1 can also be inclined relative tothe connecting part 3 in this embodiment.

The invention is not limited to the embodiments that were describedabove and are illustrated in the figures. For example, the connectingpart 3 may also be integrally molded to the cover. In this case, thereservoir may have a conventional cup-like shape with a straight bottomsurface that does not feature a connecting part. The cover provided withthe connecting part can be attached to the reservoir after it is filledand the fluid reservoir can then be inserted into the opening of a paintspray gun that is held in an upside down position. The paint spray gunis subsequently turned over such that the fluid reservoir is situated onthe upper side of the paint spray gun. The venting of the fluidreservoir is realized, e.g., by the opening of a vent valve provided onthe bottom of the fluid reservoir or by piercing an initially closedventing duct with the aid of a pin or the like. The utilization of avent valve that can be reclosed after the paint spray gun is used or avent opening that can be resealed provides the advantage that the fluidreservoir can also be used for storing paint that was not used in itsentirety.

1. A fluid reservoir for a paint spray gun, said reservoir comprising acup shaped receptacle having a first central axis for holding paint tobe gravity fed into a paint spray gun, a cover that is attached to andcloses the receptacle and a conical bottom that is attached to an outletspout having a second central axis through which paint in saidreceptacle can flow by gravity into a paint spray gun, said outlet spoutbeing integrally molded as part of the reservoir and serves for fixingthe fluid reservoir on a paint spray gun to enable paint in saidreceptacle to flow by gravity through said outlet spout into said paintspray gun, said outlet spout composed of a tubular connection piece ofpreselected wall thickness that includes a hollow cylindrical frontarea, an adjacent external thread for being screwed into an internalthread on an inlet port of a paint spray gun, a screw-type wedge abovethe external thread for rapid coupling to a paint spray gun and an upperinsert area with an annular contact surface to receive a filter, andwherein the screw type wedge is formed by a wedge shaped projection witha wedge surface that extends over approximately half the circumferenceof the outlet spout for engagement with a corresponding mating surfaceon a paint spray gun; a flexible transition area composed of an elasticnon-embrittled plastic material having a high PE content formed at theconical bottom of the reservoir where it joins with the outlet spout toprovide flexibility in order to enable adjustment of the inclination ofthe first central axis of the receptacle of the reservoir relative tothe second central axis of the outlet spout of the reservoir so that thereservoir can be maintained in a vertical orientation, said transitionarea being characterized by a radius to insure that the transition areais not damaged when the outlet spout is operatively fixed in a paintspray gun to enable gravity flow of reservoir content into the paintspray gun and the reservoir is inclined relative to the outlet spout sothat the first central axis of the receptacle of the reservoir can bemaintained vertical regardless of the inclination of the second centralaxis of the outlet spout of the reservoir, said transition area having awall thickness that is at least 30% less than the preselected wallthickness of the outlet spout whereby during gravity feed of paint fromthe receptacle to a paint spray gun, the receptacle can be placed stablyat a vertical orientation with respect to the second central axis of theoutlet spout and thereby assure continuous gravity feed of paint intothe paint spray gun regardless of the paint spray gun's orientation andthus allows for uninterrupted operation of the paint spray gun.
 2. Thefluid reservoir according to claim 1, wherein the outlet spout isintegrally formed with the receptacle.
 3. The fluid reservoir accordingto claim 1, wherein the outlet spout is integrally formed with thecover.